Apple Watch Ultra no longer fast charging

I was able to fast charge my Apple Watch Ultra for more than a year. Since about a couple of weeks, it is no longer the case.

I have restarted my watch, as told in other posts. To no avail.

I use the same chargers and the original charging puck. Nothing has changed. Now, it takes about three and more hours to get about 80%. I have the latest IOS and the latest Apple Watch OS.

Any clues?

Apple Watch Ultra 2, watchOS 26

Posted on Jan 6, 2026 12:27 PM

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Posted on Jan 7, 2026 8:15 AM

The same issue with my Ultra 3, optimised charging is not working if you wear the watch 24/7 and try and charge it when around 20% charge level remaining. It will often not charge at all, presumably because it has learned some usage pattern.

I have just had the low battery warning, put it on charge and 30 minutes later, no increase in charge level at all.

If optimised charging is turned off, then it behaves itself, so not a charger/cable issue.

This setting may be ok for a standard series watch where a user charges it every night, but not the ultra 3 with its longer battery life.

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Question marked as Top-ranking reply

Jan 7, 2026 8:15 AM in response to sberman

The same issue with my Ultra 3, optimised charging is not working if you wear the watch 24/7 and try and charge it when around 20% charge level remaining. It will often not charge at all, presumably because it has learned some usage pattern.

I have just had the low battery warning, put it on charge and 30 minutes later, no increase in charge level at all.

If optimised charging is turned off, then it behaves itself, so not a charger/cable issue.

This setting may be ok for a standard series watch where a user charges it every night, but not the ultra 3 with its longer battery life.

Apple Watch Ultra no longer fast charging

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